Page:Illustrations of Indian Botany, Vol. 2.djvu/23

Rh filling the berry, excavated into numerous unequal many seeded cells. No true partitions, but spurious ones, arising from the substance of the placenta, of variable thickness and very fragile" or as explained by himself in English " a fleshy receptacle formed by the tube of the calyx into a unilocular berry filled with a spongy placenta, which is hollowed out into a number of irregular cells in which the seeds are placed, the dissepiments being nothing more than thin ''portions of the placenta. Don. Edin. New Phi. Jour. 1826.''

"Fruit large, spherical, crowned by the limb of the calyx, indehiscent; the fruit is the tube of the calyx divided horizontally into two chambers or parts, the upper division 5-9 celled, the lower division 3 celled; the dissepiments membranous separating the cells; the placentas of the upper part of the fruit fleshy, reaching from the parietes to the centre; those of the lower divisions progressing irregularly from the bottom of the fruit." D.C. prod. — Pg. 3.

On the opposite side Lindley examines the question at great length and is followed by Arnott, who gives a more brief but I think better exposition of the argument on this side than his leader. 1 subjoin both in full.

"The fruit of the Pomegranate is described by Gartner and DeCandolle as being divided into two unequal divisions by a horizontal diaphragm, the upper half of which consists of from 5 to 9 cells, and the lower of 3; the cells of both being separated by membranous dissepiments; the placentæ of the upper half proceeding from the back to the centre, and of the lower irregularly from their bottom; and by Mr. Don as a fleshy receptacle formed by the tube of the calyx into a unilocular berry, filled with a spongy placenta, which is hollowed out into a number of irregular cells. In fact, if a Pomegranate is examined, it will be found to agree more or less perfectly with both these descriptions. But it is clear that a fruit as thus described, is at variance with all the known laws upon which compound fruits are formed. Nothing, however, is more common than that the primitive construction of fruits is obscured by the additions, or suppressions, or alterations, which its parts undergo during their progress to maturity. Hence it is always desirable to obtain a clear idea of the structure of the ovarium of all fruits which do not obviously agree with the ordinary laws of carpological composition. Now, a section of the ovarium of the Pomegranate in various directions, if made about the time of the expansion of the flowers before impregnation takes place, shews that it is in fact composed of two rows of carpella, of which three or four surround the axis, and are placed in the bottom of the tube of the calyx, and a number, varying from five to ten, surround these, and adhere to the upper part of the tube of the calyx. The placenta of these carpella contract an irregular kind of adhesion with the back and front of their cells, and thus give the position ultimately acquired by the seeds that anomalous appearance which it assumes in the ripe fruit. If this view of the structure of the Pomegranate be correct, its peculiarity consists in this, that, in an order the carpella of which occupy but a single row around the axis, it possesses carpella in two rows, the one placed above the other, in consequence of the contraction of the tube of the calyx, from which they arise. Now, there are ninny instances of a similar anomaly among genera of the same order, and they exist even among species of the same genus. Examples of the latter are, Nicotiana multivalvis and Nolana paradoxa, and of the former Malope among Malvaceae; polycarpous Ranunculaceae as compared with Nigella, and polycarpous Rosaceae as compared with Spiraea. In Prunus I have seen a monstrous flower producing^ number of carpella around the central one, and also in consequence of the situation, upon the calyx above it; and., finally, in the Revue Encyclopedique (43-762), a permanent variety of the apple is described, which is exactly to Pomaceae what Punica is to Myrtaceae. This plant has regularly 14 styles and 14 cells, arranged in two horizontal parallel planes, namely, 5 in the middle, and 9 on the outside, smaller and nearer the top ; a circumstance which is evidently to be explained by the presence of an outer series of carpella, and not upon